Changes in Sugar Metabolism and Fruit Quality of Different Pear Cultivars During Cold Storage

Abstract

This study evaluated the changes in sugar metabolism and fruit quality of different pear cultivars during cold storage using seven major commercial pear cultivars belonging to different Pyrus species, such as P. bretschneideri Rehd. (“Huangguan,” “Yali”), P. pyrifolia Nakai. (“Wonhwang,” “Hosui”), P. ussuriensis Maxim. (“Jingbai,” “Nanguo”), and P. communis L. (“Bartlett”). The firmness, respiration rate, titratable acidity, total soluble solids, sugar content, and enzyme activity of the seven pear cultivars were investigated. SPSS was used for analyzing the significance of different indexes. Results showed that fructose was the dominant sugar, accounting for > 60% of total sugars, followed by glucose and sucrose. The respiration peak of almost all cultivars appeared within 60 days. The levels of fructose, glucose, sucrose, and total soluble solids increased within 90 days and then generally decreased. Acid invertase showed the highest activity among all pear cultivars, followed by neutral invertase, sucrose synthetase, and sucrose phosphate synthetase during storage.